Properties of water Flashcards
Define density
mass per volume
What does high density mean?
heavy for its size
What does low density mean?
light for its size
Density in water is ____ times greater than air
800
What does high density in water allow for? (2)
- natural buoyancy
- good for generating thrust
What does natural buoyancy mean?
- not sinking or floating
What are 2 advantages to dense water?
- saves energy (buoyancy)
- pushing against dense water thrusts them foreward
What is a major disadvantage to dense water?
- high resistance to motion (drag)
- holds fish back from gliding
Define viscocity
- internal friction of water/molecular cohesion
Viscosity of water is ___ times greater than air
50
What are the major disadvantages of high viscosity in water?
- drag
- turbulence
What are 2 adaptations to viscos water?
- streamlining
- high proportion of swimming muscles (able to generate thrust
Define streamlining
- fusiform shape in aerodynamic
What are 3 adaptations to overcome the fact that water is virtually incompressible?
- gills
- sound detection/transmission
- lateral line system
What are gills/what do they do?
- ventilations
- gas exchange organ
- pump out water
Sound in water moves ____ times faster than air
- 5
What allows for sound detection?
- inner ear and swim bladder
What is a swim bladder?
- air filled cavity
What is the lateral line system and what is it used for? (3)
- senses sound/vibrations in water
USED FOR - locating other fish/objects
- body position
- communication
What is the universal solvent?
oxygen
What does it mean that oxygen is limiting?
- it is limiting to cellular respiration (limitation to fish)
What does DO mean?
- dissolved oxygen
What is the DO of water?
1-10ml/L
Why is oxygen in water small?
- bc of low solubility
What is the DO of air? What % of air is oxygen?
- 210mlL
- 21%
What are 2 examples of electrolytes?
- Na+
- Cl-
How are nutrients diffused out?
simple diffusion
What are organic compounds and nutrients good for? what are 2 examples?
- waste elimination
- ammonia, CO2
What helps with waste elimination?
- diffusion gradients of nutrients across bodies
What are 2 examples of xenobiotics
- metals
- pesticides
How are xenobiotics taken up?
- across body surface
What is light penetration?
- attenuation of light with depth
- depth it can penetrate is limiting
What is another name for the euphotic zone?
- sunlight
Describe the euphotic zone
- where light is penetrated
- shallow in coastal zone
- most phytoplankton/algae
What is first degree productivity?
- lots of phytoplankton/algae = more fish
What is another name for disphotic zone? how deep does it go?
- twilight
- up to 1000 m
Describe disphotic zone
- low light
- few fish
What are 3 adaptations of fish in disphotic zones?
- barbels
- electric organs
- luminescence
what are the functions barbels?
- sensory
What is counter illumination?
- closer to light and above = fish below can see shadow
- light at bottom of body changes contrast for predators
Describe the aphotic zone
- dark
- fewer known fish
- similar specializations for darkness
